Background T cell senescence is one of the key components of immunosenescence, closely associated with the occurrence and development of various age-related diseases and tumors. However, there is a lack of research exploring the molecular mechanisms of T cell senescence based on transcriptomics.

Objective To establish a T cell senescence model and perform transcriptome sequencing, then use bioinformatics methods to analyze potential molecular mechanisms and identify key genes during T cell senescence.

Methods T cells were isolated from human peripheral blood mononuclear cells, after a brief period of in vitro culture for expansion, the cells were randomly divided into senescent T cell group, cultured in a medium containing 20mg/mL D-galactose, and normal control group, cultured in a medium without D-galactose. After 48 hours of culture, changes in telomerase activity, telomere length, senescence-associated secretory phenotype, and β-galactosidase activity were assessed in T cells before and after cell senescence. mRNA transcriptome sequencing of the cell models was performed, and bioinformatics methods were used to analyze significantly differentially expressed genes (DEGs). Enrichment analysis and the construction of protein-protein interaction (PPI) networks were conducted on the DEGs to analyze the functional status of DEGs during T cell senescence and to screen for key genes.

Results After 48 hours of D-galactose treatment, T cells showed impaired telomere function, increased expression of p21 gene and protein, increased secretion of cytokines, enhanced β-galactosidase activity, and increased intracellular lipid synthesis. Enrichment analysis revealed that senescent T cells showed enhanced activity in cytokine-cytokine receptor interaction, p53, PI3K/Akt/mTOR, NF-kappaB signaling pathways. PPI network analysis suggested that ISGs and RPs gene families might play a crucial role in T cell senescence.

Conclusion Senescent T cells exhibit telomere dysfunction, lipid metabolism disorder, enhanced pro-inflammatory capacity, and increased activity of cell senescence-related signaling pathways. Moreover, the ISGs and RPs gene families may play significant roles in the process of T cell senescence.